Earlier we reported about a method of finding out number of connections issued against your SIM through sending an SMS – look at following.
Simply point your browsers to this url: http://www.pta.gov.pk/668/
By the way, service is still not officially launched, so you may find record not found thingy.
Also make sure that you go to respective service center to find out mobile connections that are your name. Get those numbers blocked immediately, which you are not using. At times, this can be very sensitive as number under your name can be used for some illegal act, so get it blocked, right now!